Ultrawide-band linear-circular polarization converter

Abstract

In an ultrawide-band linear-circular polarization converter, in a noncircular waveguide which has negative-phase characteristics in which a phase gradually decreases in accordance with an increase in a frequency over an ultrawide-band frequency range, a dielectric structure which has positive-phase characteristics, in which a phase gradually increases in accordance with an increase in a frequency, having a complementary relationship with the negative-phase characteristics in the ultrawide-band frequency range is provided.

What is claimed is:  
     
       1. An ultrawide-band linear-circular polarization converter comprising: 
       a waveguide having two orthogonal axes, which consist of a long axis and a short axis, in cross-section with different dimensions, the waveguide having negative-phase characteristics, wherein a phase of the long-axis and a phase of the short-axis have different phase delays as waves propagate through the waveguide in a direction of the long-axis and the short-axis, and a phase difference between the long-axis and the short-axis gradually decreases as a frequency increases within an ultrawide-band frequency range; and  
       a dielectric member which extends along the short axis in the waveguide and which is arranged in a waveguide axis direction, the dielectric member having positive-phase characteristics, wherein the phase of the long-axis and the phase of the short-axis components have different phase delays as waves propagate through the dielectric member in the direction of the short-axis and the long axis, and the phase difference between the long-axis and the short-axis gradually increases as the frequency increases within the ultrawide-band frequency range,  
       wherein complementary phase characteristics combining the negative-phase characteristics and the positive-phase characteristics are exhibited in accordance with an arrangement of the dielectric member.  
     
     
       2. An ultrawide band linear-circular polarization converter according to  claim 1 , wherein said waveguide is an elliptic waveguide in cross section of a waveguide passage. 
     
     
       3. An ultrawide-band linear-circular polarization converter according to  claim 1 , wherein: 
       the cross section view of the dielectric member comprise edge parts extending in the waveguide passage of said waveguide that are thinner than the middle portion between the edge parts of the member.  
     
     
       4. An ultrawide-band linear-circular polarization converter according to  claim 1 , wherein: 
       a ridged conductor structure is positioned at the inner wall of a noncircular waveguide in cross section of a waveguide passage.  
     
     
       5. An ultrawide-band linear-circular polarization converter according to  claim 1 , comprise: 
       the dielectric member positioned at one side of an inner wall of the waveguide such that, when measured from a top surface of the waveguide, a height of the dielectric member stays constant from left edge part to half way to middle portion, then increases and stays constant until half way close to the right edge, then decreases and stay constant, when viewed from a cross sectional view of the member.  
     
     
       6. An ultrawide-band linear-circular polarization converter according to  claim 1 , comprising: 
       the dielectric member having both sides faces extending in a longitudinal direction cut inwardly in a generally triangular shape when viewed from a cross sectional view of the member.  
     
     
       7. An ultrawide-band linear-circular polarization converter according to  claim 1 , comprising: 
       the dielectric member having both side faces extending in a longitudinal direction cut inwardly in a generally rectangular shape when viewed from a cross sectional view of the member.  
     
     
       8. An ultrawide-band circular polarization converter according to  claim 1 , when viewed from the cross sectional view of the waveguide comprising: 
       a semi-circular shaped dielectric member positioned at one side of an inner wall of the waveguide such that a height of the dielectric member, when measured from a top surface of the waveguide, increases from edge parts to the middle portion of the member.  
     
     
       9. An ultrawide-band linear-circular polarization according to  claim 1 , when viewed from the cross sectional view of the waveguide comprising: 
       a triangular shaped dielectric member positioned at one side of an inner wall of the waveguide such that a height of the dielectric member, when measured from a top surface of the waveguide, increases from the edge parts to the middle portion of the member.